Gelatin coating compositions containing a mixture of an acetylenic ethylene oxide derivative and an anionic surface active agent



United States Patent GELATIN COATING COMPOSITIONS CONTAINING A MIXTURE OF AN ACETYLENIC ETHYLENE OXIDE DERIVATIVE AND AN ANIONIC SUR- FACE ACTIVE AGENT William J. Knox, Jr., Rochester, N.Y., assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Filed June 22, 1965, Ser. No. 466,073

Int. Cl. G03c 1/72 US. CI. 96-94 8 Claims ABSTRACT OF THE DISCLOSURE Film-forming compositions containing a hydrophilic film-forming material such as gelatin and a mixture of an acetylenic ethylene oxide derivative and an anionic surface active agent selected from sodium maleopimarate, dodecyldiphenyl ether disulfonate or isopropylnaphthalene sulfonate as a coating aid and which are useful in preparing photographic layers are described.

This invention relates to image-forming layers and to hydrophilic colloid compositions for coating them, and more particularly, to new combinations of surfactants which are useful in the preparation of such layers.

Many image-recording systems use sensitive materials comprising a support such as glass, or a thin, flexible film of metal, paper or plastic, covercoated with one or more layers comprising hydrophilic film-forming binders such as gelatin. Silver salt-sensitized photographic materials, for example, are usually coated from aqueous gelatin on film base or paper. The layer containing the silver salt is frequently coated in combination with several other gelatin layers which serve, for example, as carriers for reflective pigments, antihalation dyes or filter dyes, or as undercoatings to improve adhesion, overcoatings for abrasion resistance, and the like.

In the coating of such hydrophilic colloid layers, particularly those containing gelatin, it has been customary to employ surface-active agents as coating aids to improve the quality and uniformity of the layers and the ease and reproducibility of their application. The surfactants used often influence other characteristics than the coating performance; e.g., surface roughness, permeability to processing solutions, and the like.

Saponin, a naturally occurring material prepared from quillaia bark, has been widely used as a gelatin coating aid. Being of natural origin, saponin varies in composition according to the source, the method of extraction, and the like, and commercial saponin may include impurities which produce undesirable effects in photographic materials. Saponin has been a reasonably effective coating aid in many applications. However, newer coating procedures which involve increased coating speeds, the application of liquid coating compositions to set, but undried underlayers, and the simultaneous coating of two or several layers, have increased the requirements of a satisfactory coating aid and have rendered saponin and many other prior art coating aids inadequate.

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Certain synthetic materials such as sodium maleopimarate, sodium dodecyldiphenyl ether disulfonate, and isopropylnaphthalene sulfonate, have been disclosed as coating aids useful in preparing hydrophilic colloid layers; however, when used alone in certain coating operations, they do not impart to the final product sufficient rewettability for certain processing systems. Photographic gelatin layers, coated with these agents as the sole coating aids, may process unevenly because of inadequate wetting by the processing solutions. Effects have been made to overcome this difiiculty by admixture with saponin, which, however, introduces the difficulties discussed earlier.

It is an object of this invention to provide new and improved combinations of surfactants useful in coating layers of hydrophilic film-forming compositions.

It is another object to provide new and improved coating aid combinations for aqueous photographic gelatin compositions.

It is a further object of this invention to provide new surfactant combinations which impart excellent adhesion and good surface characteristics to the coating.

It is a still further object of this invention to provide new surfactant combinations which, when used as coating aids, impart desirable surface roughness to the coated layers and which reduce the incidence of repellencies in the coating.

It is another object of this invention to provide aqueous hydrophilic colloid compositions comprising new surfactant combinations which impart increased wettability to the layers coated from these compositions and an increased coefficient of friction to the surface of the resulting layers.

It is another object of this invention to provide silver halide-hydrophilic colloid photographic layers comprising new surfactant combinations which endow the final product with improved wettability characteristics and an increased coefficient of friction.

It is still another object of this invention to provide photographic overlayers and underlayers of hydrophilic colloids, and in particular, of gelatin, comprising new surfactant combinations which allow the layers to be prepared with greater ease and higher quality and which allow very good wettability of these layers by processing solutions.

Another object of this invention is to provide imageforming materials having improved rewettability characteristics.

A further object is to provide a process for coating hydrophilic colloid layers comprising the step of adding to an aqueous hydrophilic colloid composition an anionic surface-active agent in admixture with an auxiliary coating aid which improves the rewettability characteristics of the coated layer.

Still further, it is an object of this invention to provide a procedure enabling the simultaneous application of silver halide-hydrophilic colloid photographic emulsion layers and gelatin overlayers and underlayers thus facilitating rapid preparation of photographic elements.

Another object is to replace saponin in coating aid combinations, with synthetic materials, of which the com- 3 position and purity are more consistent from batch to batch.

I have achieved these objects by adding to liquid hydrophilic colloid compositions, intended for coating photographic layers, certain anionic surface-active agents in admixture with acetylenic ethylene oxide derivatives having the following generic structure:

CH3 CH3 CH3 CH3 CHICHCHiC-CEC-ECHZCHCHQ J H: $112 CH1 CH2 m n H OH I where m+n=3 to 30. Typical examples of the latter are those acetylenic compositions wherein mi-l-n is 3.5 (Compound II), 5 (Compound III), (Compound IV), (Compound V), and 30 (Compound VI) These acetylenic agents, when added to certain anionic surface-active agents such as sodium maleopimara-te, sodium dodecyldiphenyl ether disulfonate (Benax 2A1, sold by Dow Chemical Company), or isopropylnaphthalene sulfonate :(Aerosol OS sold by American Cyanamide Company) in ratios ranging from 1:9 to 9: 1, form mixtures which may serve as unique coating aids in the application of certain emulsions to paper and film base using current coating techniques.

The anionic surfactants, when used as coating aids, (1) are photographically inert, (2) enable emulsion and related coatings to be applied to film base and paper without repellencies and other coating defects, and (3) maintain sufiicient surface roughness at the coating surfaces for efficient handling. They fail, however, to impose adequate rewettability on the final product. The addition of the acetylenic compounds to these surfactants eliminates this inadequacy.

The compounds of structure I are tolerant to admixture With even high ratios of ionic surfactants. They are compatible not only with ionic surfactants, but also with other non-ionic coating aids. In particular, they form highly advantageous and synergistic coating aid combinations with anionic surfactants of the classes commonly used as coating aids for gelatin and other photographic colloids. Such compounds are compatible with a wide range of ratios of surface-active agents such as alkyloxypolyalkyloxyalkanols, alkylphenoxypolyalkyloxyalkanols, sulfates, sulfonates, sulfonic acids, sulfosuccinates, esters, amides, amino acids, ammonium salts, fluorochemicals, and poly(ethylene oxide) condensates of poly- (propylene oxide).

The surfactant mixtures of my invention can be used in applying aqueous photographic layer coating compositions in which the film-forming binder consists entirely of gelatin, or of gelatin and one or more other hydrophilic colloid materials. For example, materials such as copoly(ethyl acrylate-acrylic acid) (80:20) may be used with gelatin to act as a gel extender, to reduce the modulus of elasticity, or the like. Colloids having the property of increasing covering power such as copolymers of acrylic acid and N-substituted acrylamide may also be used in admixture with gelatin as well as other collodial materials to impart particular physical characteristics -to the gelatin coating. Furthermore, these surfactant mixtures may be used to apply not only the sensitive silver halide-hydrophilic colloid layers, but also in coating the other hydrophilic colloid layers which comprise a photographic element, such as undercoating, reflective pigment, antihalation, overcoating, mordant-carrying or filter-carrying layers and the like.

To illustrate the practice of this invention a number of coatings were prepared by the simultaneous application to baryta coated photographic paper base of a silver halide-gelatin photographic emulsion and a clear gelatin overcoat by a multilayer technique such as described in Russells US. Patent No. 2,761,791. The relative proportions of anionic surfactant to Compound III (Surfynol 450, sold by Air Reduction Chemical Carbide Company), the concentrations of surfactant used in each case, and the results obtained by measuring the developer spread, coeflicient of friction and repellencies are recorded in the following tables.

EXAMPLE 1.-SODIUM MALEOPIMARATE AND COMPOUND III Surfactant Coneen- Repellencles tratlon in Wet Developer Coef. of (7.6 It!) pread Friction Emulsion Overcoat (cm?) Dull Bright (BJ (tr/ Sodium meleopimarate/Compound III:

10/0 0. 0 0. 5 3. 80 0. None 3 0. 13 0. 5 4. 15 0. 46 None None 0. 25 0. 5 4. 90 0. 47 None None 0.5 0. 5 0. 45 None N one 0. 0 0. 5 6. 16 0. 46 5 1 0. 13 0. 5 4. 90 0. 45 None None 0. 25 0. 5 5. 72 0. 47 3 1 0. 5 0. 5 5. 72 0. 45 None None 0. 0 0. 5 6. 16 0. 45 None 1 0. 13 0.5 5. 72 0. 45 1 2 0. 25 0. 5 0. 43 None None 0. 5 0. 5 15. 90 O. 43 N one 1 0. 0 0. 5 16. 0. 45 1 None 0. 13 0. 5 7. 07 0. 45 None 1 0. 25 0. 5 6. 16 0. 45 1 None 0. 5 0. 5 7. 67 0. 43 None None 0. 0 0. 5 15. 90 0. 44 None None 0. l3 0. 5 16. 6O 0. 44 None N one 0. 25 0. 5 O. 43 None None 0. 5 0. 5 12. 60 0. 43 None None 0. 0 0. 5 16. 60 0. 47 None None 0. 13 0. 5 16. 60 0. 46 None 1 0. 25 0. 5 16. 60 0. 46 None None 0. 5 0. 5 16. 60 0. 46 None None 3. 46 0. 49 None None 0. 0 5. 0 10. 70 0. 51 None None EXAMPLE 2.SODIUM DODECYLDIPHENYL ETHER DISULFONATE (BENAX 2 Al) AND COMPOUND 111 m m w nun I. mm B ha W R D mm mm on we) mwm VPC 6 t n m we m W Wu C 0 m BGQBQBBBQQBIQQGB eeeeeee e mmmmmmwmwwmmmmwmimmmmmmm4m NNNNNNNNNNNNNNNN. NNNNNNN. N 9999988986968 668 89809 e mmwmmmmmmmmmmzmwwiwmwmmzzw NNNNNNNNNNNNN NNN NNNNN N U QQQQQQQQQQQQQQQOWQQQQQQQQQ 6 L fiom-hnmizlnawinw-mn vm 1 1 1111111 1 565555555555555555555555 "0 QQ0 0 0 0 0 Q0 &0 0 0 &0 0 0 0 0 0 Q0 0 0 5 n n 5 5 5 5 0 0 0 0 0 0 QQ0 0 0 0 0 0 0 0 0 0 QQ0 0 QQ 0 "m .0 D. 5 S n I .m I "a d "m m w D. m m 0 m 01 LLIIIIIIIIIII dWWWWAHHHHHHHBBBBHHHHHWHH m m M11119999444477771.1113333Mi 9 0M B CS EXAMPLE 3.-ISOPROPYLNAPHTHALENE SITIiLFONA'IE (AEROSOL 05) AND COMPOUND Surfactant Concen- Repelleneies tration in Wet Developer Coet of (7.6 it!) Friction Emulsion Overcoat Dull Bright Spread 69 e mmmmmmmmmmmmmmmmmmmmmmfi 000000000000000000000000 0 NNNNNNNNNNNNNNNNNNNNNNNN N eeeeeee eeeeeeeeeeeeeeee e H n mmmmmmmimwmmmmmmwmmmmmmio NNNNNNN NNNNNNNNNNNNNNNN N 0 0&0QQQQQQQQQQQQQQQQQQQQQQ 055000002 mmm%wnwnmmnmwmmwa55666665 0 0 QO 0 0 0 O O 0 0 0 Q0 0 Q0 0 0 0 Q0 Q0 Aerosol] Compound III bed hereinabove, and

In satisfactory operation it is considered that the prodand scope of the invention as descri uct should have a developer spread of at least 5.72 cm. as defined in the appended claims. and a coefiicient of friction greater than 0.29. I claim:

fi e

e n mm mm dem H n1 H H km N m m H d 6C H C H H H g m m c o o c c o m .i mm mm .10... s C 2 2 P e H H H H m m b c w o c c o C H FIIIL kM a c wmn H H t 6 C C .13 3

wmw Am gr 6 .md

In the above data repellencies refers to the number of dull and uncoated spots in the area designated whether 25 square feet or 7.5 square feet.

Developer spread was determined by delivering in a standard manner one cc. of developer solution to a surface of photographically sensitized paper carrying a clear gelatin overcoat, and measuring the area which develops in a period of 30 seconds. This test indicates how eifectively an emulsion will wet. A developer spread of 4.0 crn. or more is desirable.

The coetficient of friction was determined by placing the coated side of photographically sensitized paper carrying a gelatin overcoat against the uncoated side of a similar sheet. The coefi'icient of friction was measured where m+n=5 and an anionic surface active agent selected from the group consisting of sodium maleopi- .70 marate, dodecyldiphenyl e'ther disulfonate and isopropylnaphthalene sulfonate, the acetylenic ethylene oxide in considerable dederivative constituting 990% of said coating aid. tail with particular reference to certain preferred emto obtain the slickness of the gelatin coating. Difiiculties occur in stacking coated sheets when the coefiicient of friction is less than about 0.25.

The invention has been described 2. A composition in accordance with claim 1 containbodiments thereof, but it will be understood that variaing sodium maleopimarate as an anionic surface active tions and modifications can be efiected within the spirit agent.

3. A composition in accordance with claim 1 con taining dodecydiphenyl ether disulfonate as an anionic surface active agent.

4. A composition in accordance with claim 1 containing isopropylnaphthalene sulfonate as an anionic surface active agent.

5. A gelatin-silver halide photographic emulsion containing as a coating aid therein a mixture of an acetylenic ethylene oxide derivative represented by the structural formula:

where m+n=5 and an anionic surface active agent selected from the group consisting of sodium maleopimarate, dodecyldiphenyl ether disulfonate and isopropyl- 8 naphthalene sulfonate, the acetylenic ethylene oxide derivative constituting 9-90% of said coating aid.

6. A gelatin silver halide photographic emulsion in accordance with claim 5 containing sodium maleopimarate as an anionic surface active agent.

7. A gelatin-silver halide photographic emulsion in accordance with claim 5 containing dodecyldiphenyl ether disulfonate as an anionic surface active agent.

8. A gelatin-silver halide photographic emulsion in accordance with claim 5 containing isopropylnaphthalene sulfonate as an anionic surface active agent.

References Cited UNITED STATES PATENTS 2,823,123 2/1958 Knox et a1. 9694 3,038,804 6/1962 Knox et a1. 96--94 3,255,013 6/1966 Dersch et al. 9694 I. TRAVIS BROWN, Primary Examiner.

US. Cl. X.R. 106-125. 

